Missile launching system



Feb. 18, 1964 J. REEVES 3,

MISSILE LAUNCHING SYSTEM Filed Jan. 8, 1962 7 Sheets-Sheet 1 bLP FIG. 2

INVENTOR LAWRENCE J. REEVES FIG. 1

ATTORNEYS Feb. 18, 1964 J. REEVES MISSILE LAUNCHING SYSTEM Filed Jan. 8', 1962 7 Sheets-Sheet 2 L. J. REEVES MISSILE LAUNCHING SYSTEM Feb. 18, 1964 T Sheets-Sheet 3 Filed Jan. 8, 1962 mm QM Feb. 18, 1964 L. J. REEVES MISSILE LAUNCHING SYSTEM '7 Sheets-Sheet 4 Filed Jan, 8, 1962 an QR S Feb. .18, 1964' J. REEVES MISSILE LAUNCHING SYSTEM '7 Sheets-Sheet 5 Filed Jan. 8, 1962 TQQ 1| 1|: hg xm mm \m Wm km mm um at $95 Feb. 18, 1964 J. REEVES MISSILE LAUNCHING SYSTEM Filed Jan; 8; 1962 '7 Sheets-Sheet 6 Ems-m XOm 14mm u PS5 2 5m mm\ km 2 5m k w Sw ozwomj ml- H- s 0 (9-11-0010 Feb. 18, 1964 L. J. REEVES 3,121,369

MISSILE LAUNCHING SYSTEM Filed Jan. 8, 1962 '7 Sheets-Sheet 7 5 mmm mmm O EJME 55 mm Q9 kww w men Eu 0.5 m woo 6m? 6m 26 E o .w wwm l... R R

5 m nmw v m m8 3 Z3 25 5 3.. 6

6 5 a z m 3 A 2+ t 3 80 6w J mm at United States Patent Ofi ice 3,121,369 Patented Feb. 18, 1964 3,121,369 MISSILE LAUNCHING SYSTEM Lawrence J. Reeves, Palo Alto, Calif-2, assignor, by mesne assignments, to the United States of America as represented by the Secretary of the Navy Filed Jan. 8, 1962, Ser. No. 165,049 32 Claims. (Cl. 89-137) This invention relates to a system for preventing the launching of a missile at an unsafe angle, and more particularly to a system capable of indicating the coincidence of safe missile firing conditions and preventing firing when dangerous missile fallback conditions exist.

In recent years, vertically launched missiles have come to play a vital role in national defense. Such missiles may be launched from land, surface ships, or submarines during combat or test exercises. In the course of developing vertically launched missiles a need has arisen to insure prevention of firing whenever conditions exist which would allow a dud missile or dummy test vehicle to fall back on the launcher. It is, therefore, desirable to allow the initiation of missile or test vehicle firing only when such a launching would propel the missile fired a sufiicient lateral distance from the launcher. Thereby, the possibility of a collison between the launcher and the missile, should fallback occur, would be eliminated.

The present invention utilizes an electronic-electromechanical computing-indicating system for instructing the missile launching officer when it is safe to fire and for preventing completion of the firing circuit when it is unsafe to fire. To avoid fallback the launcher may be listed to a safe angle. In the instant invention, when static lists are imposed, the angle of list or heel actuates a servo loop in the Safe Launch Angle Gate System, hereinafter entitled SLAG system. The actuated servo loop then operates indicators, and relays and switches for safety interlocks in the missile launcher firing mechanism. .To allow for the dynamic condition of roll velocity SLAG utilizes an analog angle computer which operates to indicate the percentage of GO or safe firing time existing at any given time as well as instantaneous roll angle. These indications have a fixed time delay to allow sufiicient time for missile launch initiation and for the missile to clear the launcher muzzle. Thus, the computer predicts the angle, with respect to the vertical, of the launcher at the time the missile will clear the launcher. Of course, the computer may also act to condition a relay system to complete or interrupt a firing circuit.

Accordingly, an object of the present invention is the provision of a system for indicating the existence of safe firing conditions and preventing firing when dangerous missile fallback conditions exist.

Another object is to provide a system for allowing initiation of missile firing only when conditions exist thereby indicating that a missile fired would be propelled a sufiicient lateral distance from the, launcher to eliminate the possibility of a collison between the launcher and the missile should fallback occur.

A further object of the invention is the provision of a system which actuates relays and switches for safety interlocks in a missile launcher firing system when the launcher is listed to a satisfactory angle to thereby eliminate the hazard of missile fallback on the launcher.

Still another object is to provide a system for indicating static list conditions and future dynamic roll conditions and for respectively allowing and preventing completion of a missile firing circuit for missile launching during safe and hazardous periods of time.

Yet another object of the present invention is the provision of dual systems for alternate or simultaneous operation which indicate static and dynamic conditions of a missile launcher and prevent the initiation of missile launching where the static orientation of the launcher provides hazardous fallback conditions or where the dynamic roll velocity conditions of the launcher are such as to provide hazardous fallback conditions when the missile clears the launcher muzzle.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. 1 is a rear view illustrating a missile launching ships physical and mathematical orientation.

FIG. 2 is a partial top view of FIG. 1 further illustrating a missile launching ships physical and mathematical orientation.

FIGS. 3A, 3B, 3C, and 3D are portions of a schematic diagram for the SLAG system.

FIG. 4 is an illustration depicting the interrelationship of FIGS. 3A, 3B, 3C, and 3D when connected to form the SLAG system.

FIG. 5 is a schematic diagram of an alternate embodiment of a portion of the SLAG system.

FIGS. 6A and 6B are, respectively, left and right portions of a block diagram of the SLAG analog angle computer.

Where missiles are launched in a substantially vertical manner from a launcher the requirement exists that the launcher be at such an angle of static list or dynamic roll that the danger of fallback damage to the launcher is prevented. The safe launch angle, of course, is determined by the physical launcher location on the platform or vessel and the method of missile launch.

The fallback analysis embodied in the instant invention and presented herein is two-fold; one being for a static angle oflist and one being for a-dynamic roll-rate angle. It should be understood that the mathematical equations hereinafter set forth are general and may be modified to fit a variation of launching parameters and criteria. It should be further understood that the assumptions are made that roll motion is sinusoidal, and that muzzle velocity and gravity are constant. It is further assumed that the launcher or ship maintains generally constant vertical motions and that there are no violent motions of the ship after launch. Reference to the mathematical and physical orientations of the launching ship as illus trated in FIGS. 1 and 2. will be helpful in the following mathematical considerations of fallback analysis.

Initial missile motions are: Y =V cos 0 +(e sin fi -l-b cos 0 M +(d Cos (To-e Sin a' )d +li (l) and X l sin 66+ (e cos 0 -h sin 0 +'(d cos a b cos mam-S (2) where,

Y: distance missile travels above launch point (LP) Y=vertical velocity V Y =initial vertical velocity of missile (with respect to ship) X=rnriss distance (perpendicular to ships longitudinal centerline (Q) X=horizontal velocity X =initial vertical velocity of missile (with respect to ship) e=height of LP above shipscenter of rotation (C b=LP distance from ships longitudinal ccnterl-ine (Q) d=distance fore from ships transverse centerline (Q) h=heave Ii=heave rate S=sway =sway rate V =muzzle velocity of missile =roll angle l9=roll rate (angular velocity) a=pitch Zr=pitch rate (angular velocity) 6=yaw All sub Os indicate initial conditions; applicable equations for motion are:

where ships motion is not constant missile travel is:

(X Xo) ;i@ (V sin (Jill-X (10) where X =(e cos 0-b sin 0)0 +d cos 8b sin ens, 11

and X =initial horizontal velocity of ship.

Where sh ips motion is not constant c1earance=m1ssile travelship movement,

where:

9'=roll acceleration =yaw acceleration S =sway acceleration Where ship motion is not constant flight time would also be modified slightly according to the equation:

(d cos o-b sin r) +li]dtdt where:

=pitch acceleration h=heave acceleration Due to the conditions under which the missile is to be launched, with the ship listed to one side, it may be further assumed that the motions of the ship, after launch, will be toward the vertical and away from the fallback area. Therefore, the missile travel Equations and 11 will have more significance to the SLAG system than 4 will Equations 12 and 13. The missile travel Equations 10 and 11 may, for purposes of simplicity, be reduced to:

Missile travel for a static condition, ignoring motions of the ship, would, therefore, be:

Sill 219 This miss distance X must be greater than the distance to the side over which the missile is to be launched plus one-half the missile length in order to allow a safe margin for missile tumlble. Some additional clearance may be required due to slewing of the missile and any horizontal motions of the ship should be considered with respect to the distance X to allow a proper safety margin.

T o calculate for dynamic conditions, where roll rate is considered and derived from Equations 10 and 11, it would be expressed:

2 (X- X sin 20+fe cos 0 (16) and Xt=X +X0 17) where:

0=roll or launch angle 0 Sin Xt=rniss distance with roll rate The SLAG analog angle computer should be able to predict a safe launch time from the electrical data transmitted by a vertical gyro roll angle control transformer to yield roll angle and roll rate to a prescribed accuracy.

The miss distance of the missile is given by the general Equation (14), neglecting the terms of heave, sway, yaw and pitch:

25: sin 20l- ;e0 cos 6-K (18) where, K equals a constant safety factor re-expressed from X For any given condition of roll and roll rate, this miss distance may be calculated. However, in launching the missile a value of miss distance must be calculated sometime in the future for allowing time for initiation of missile firing and time for the missile to clear the launcher muzzle.

For the purpose of analysis of the SLAG analog angle computer the motion of the ship will be assumed to be:

6l=0 +0 cos wt (19) where:

0 =static list angle 0,:roll angle w=radian roll frequency t=time and,

=0 w sin wt where:

0=roll rate (angular velocity) From Equation 10* and 20 it is obvious that:

m x m'n D l l a max. min. 2 0. 2

2|0'] max. 2 max. min. and,

6 11X. L 24 to at 26 where 0 =launch angle at time of launch and 0P6... sin )cs+td (27) where 0 =launch roll rate id. 7 Therefore,

X= sin 26 +%e20' cos 0 -K (28) It should, of course, be understood that since the roll and roll-rate conditions are recurrent, they may be re-evaluated after each cycle and the time reset to zero.

The above Equation 28 constitutes the primary elements and terms of the SLAG analog angle computer. Equating once more, however, to illustrate the derivation leading to the final computer equation, the following equation is accumulated from Equations 18 through 27.

men min.

COS

uinn min.

(ts+td)]}-K For purposes of simplicity in the computer, there is a G0 condition as an input equation to be solved,

0min. maX. min.

9L 6min.

COS

From the foregoing it can be seen that the SLAG system contains first, a device to solve Equation 15 for static semi-dynamic conditions and second, an analog 6 angle computer to solve Equation 30 for dynamic conditions.

The SLAG system, as seen in FIGS. 3A, 3B, 3C and 3D, employs two identical systems to provide fail-safe operation. That is, through the use of a switching circuit with a dual system of vertical gyros, power supplies, remote indicators, mechanism assemblies, and switching circuits, the selection of either a right system, left system or both systems is permitted. -It should, of course, be understood that only a single rather than a dual system may be employed in those instances where this fail-safe feature is not considered necessary. Where only a single SLAG system is employed it is apparent that a relay such as relay 13% of FTG. 1 would open and close the firing circuit and a system selector switch would not be needed.

Since both the left and the right systems of the dual SLAG system operate identically only one of the systems will be described in detail without a repetition of an identical description of the remaining system.- However, since both systems are illustrated in FIGS. 3A, 3B, 3C, and 31) like reference characters will designate like or corresponding parts throughout except that the system which is not described in detail will employ a prime A vertical gyro 14) is employed in the SLAG system to provide an accurate and dependable vertical reference with respect to the local vertical reference in the form of 400 cycles per second signals. This output from the vertical gyro 1t} originatesfrom a synchro pickoif 11 within the gyro 10. The output voltage from stator (14, 15, 16) of pickoff 11 is proportional to the sine of the displacement angle of the gimbals about their axes. The gyro is operated from a volt, three phase, 400 cycles per second power input through lines 211, 7,1, and 22. This input is applied to gyro 10 through a transformer 23 which is connected across lines 21 and 22 between a power-on switch 24 and rotors (12, 13) of the synchro pickofi 11.

A gravity sensitive vertical reference 31) is employed to provide electrical signals to the torquer motors 31 and 35 across respectively the resistors 32 and 33, and 36 and 37'. Maintained across respective inputs to the torquer motors 31 and 35 are compensating for tuning capacitors 34 and 38. Since the electrical output from the vertical reference 30 to the torquer motor 31 is proportional to the ships pitch and the output to the torquer motor 35 is proportional to the ships roll, the torquer motor, through the erection transformer 40, controls the gyro motor 41 which maintains and aligns the gyro spin axes to local vertical. Thus, as the gyro motor 41 opcrates to maintain and align the gyro 1!} to the local vertical, displacement of the gyros gimbals about the pitch and roll axis occurs causing an output from the synchro pickoff 11. The synchro pickoff 1-1 is oriented so that its output is proportional to the sine of the displacement angle ofthe gimbals about the roll axis. Of course, it should be understood that a second synchro pickoff could be employed in the same manner as synchro pickoif 11 except that it would be oriented so that its output would be proportional to the sine of the displacement angle of the gimbals about the pitch axis.

A second power input 25 of 115 volts, 60 cycles per second, isapplied to a power supply at 26 through a power-on switch 27. Power supply 26 supplies approximately 27 volts DC. to the various SLAG system components and for accomplishing swift erection of gyro 10 across the output of the power supply 26 is maintained a power-on indicator 28 which by illumination gives a power-on warning.

The duration of time needed for the erection of the gyro 10 through operation of the gyro motor 41 may be shortened through the use of a fast erection system. 7

This is accomplished by applying one of the outputs of the torquer motors 31 and 35 directly to the gyro motor 4 1 rather than through the erection transformer 40. A manually closable switch 50 applies D.C. from power supply 26 across a solenoid 51 having in parallel therewith a serially connected resistor 52 and diode 53. Thereby a relay 61] is actuated which, as set forth above, switches one of the outputs of the torquer motors 31 and 3 from relay contact 64 to contact 63 causing this output to be fed directly to the gyro motor 41. Also connected in parallel to the solenoid 51 is a heater 54 for actuating a thermostat 55. Upon the closure of relay 60 the thermostat 55 is switched from an open relay contact 62 to contact 61 for applying D.C. to the thermostat which is .connected in series with the parallel circuit of the solenoid 51, resistor 52 and diode 53, and heater 54. Thus, D.C. is maintained across the solenoid even after switch 50 is opened and thereby maintains the relay 60 in fast erect condition until heater 54 causes thermostat 55 to open the circuit and allow the relay to return to its normal erect condition. A fast erection indicator 67 is connected in parallel with a normal erection indicator to respective contacts 65 and 66 of relay 6!} across power lines 20 and 21. Thus an illuminated indication is received as to whether the fast or the normal erection system is in operation.

The gyro having its elements immersed in a viscous fluid employs a temperature control therein for maintaining the temperature and thereby the viscosity of the viscous fluid constant. Connected to the D.C. power supply 26 is a solenoid 71 for actuating a fan 72 connected to a fan brake 73. In parallel across the solenoid 71 is maintained a heater 74 serially connected to a thermostat 75 which applies D.C. to the heater when a decrease in temperature causes the thermostat to close the parallel circuit across the solenoid. Thus the temperature of the viscous fluid is either lowered by the fan 72 or raised by the heater 74.

The signals from the synchro piekoff 11, which are proportional to the ships roll angle, are fed to a mechanism assembly 80 which is basically a servo loop following up the vertical gyro signals. The input from the synchro pickotf 11 is received by the stator (79, 82, 83) of the control transformer 81 which has an output voltage at the rotor (84, 85) proportional to the sine of the difference between the electrical input angle and the control transformer shaft angle. This output voltage is fed to a servo amplifier 87 through a gain stabilizing resistor 86 which adjusts the gain of amplifier 87 to insure the provision of a stable and sensitive servo loop. The amplifier 87 may, for purposes of example, be a miniaturized transistor amplifier capable of delivering a maximum power output of five watts.

The output voltage of amplifier 87 energizes the control phase of a servo motor 88, which has its tap 89 returning to a DC. ground potential. A tuning capacitor 90 is employed across the control phase of the servo motor 88 in order to obtain a unity power factor at maximum efiiciency while the reference phase of the servo motor is phase shifted 90 from the control phase by a. capacitor 91. Capacitor 92 is employed across the reference phase of the servo motor 88 for tuning purposes and for reducing residual voltage.

The servo motor 88, which is a high torque-to-inertia ratio component employs a pinion to drive through a 38:1 gear head 93 and an 11:1 gear pass 94 to mechanically position a main shaft assembly. This main shaft assembly is the pointer shaft of a servo indicator pointer 95 and positions the pointer to provide a visual indication of the ships list angle. By maintaining slidable feelers on the indicator scale the amplitude of shipsroll may be indicated when the pointer 95 engaging the feelers swings through the roll angle. The main shaft assembly also positions the rotor (101, 102) of torque transmitter 119%, the direction of rotation cam 1% and the roll-angle cam 1156. The main shaft assembly also is geared 6:1 at 168 to the control transformer rotor shaft which is thereby driven through the main shaft assembly by the servo motor 88 until its rotor output voltage equals zero. When the output voltage of the control transformer rotor (84, is zero, the servo loop is nulled with respect to the vertical gyro input signal.

The main shaft assembly also drives through an Oldham coupling and mechanically positions the rotor shaft of the torque transmitter 160. The torque transmitter transmits, to a torque repeater 113 in a remote indicator 112, electrical information corresponding to the angular position of rotor (101, 192) with respect to stator (96, 97, 98). The torque repeater rotor (114, is free to turn and assumes a position with respect to the torque repeater stator (116, 117, 118) in accordance with the electrical information which is received from the torque transmitter 1%. Thus, the pointer of the remote indicator 112 is positioned and provides a visual indication of the ships list angle. Slidable feelers may also be employed on a scale of the remote indicator 112. Such feelers would be capable of being slidably positioned on the scale by the remote indicator pointer to thereby indicate amplitude of ships roll. It should, of course, be understood that a plurality of remote indicators may be provided throughout the ship.

A three phase power indicator 18 employs two illuminators connected to respective power lines 213 and 21 and to power line 22 and includes a capacitance 19 for insuring the proper time-phase constant. A power-on illumi nator 76 is employed for indicating when the power switch 77 to the torque transmitter rotor (101, 102) has been left open.

A direction of rotation cam 1114 is driven through a slip clutch 110 by the main shaft assembly and either opens or closes a micro switch 1tl5. When the ship rolls through its prescribed arc in a starboard direction the main shaft assembly rotates the cam 104 and thereby closes micro switch 165. It should, of course, be understood that the amount of roll required to close micro switch 105 may be adjusted by adjusting cam 104. The ship may then roll one degree or more in the starboard direction and then, because of slip clutch 110, back to port one degree before the micro switch opens. Thus, there is a one degree dead zone built into the direction of rotation cam 164. It should, of course, be understood that this dead zone may also be increased or decreased by the adjustment of slip clutch 1119.

The roll angle cam 11% controls the SLAG system output relay 1% and may be adjusted to any angle desired for safe launching. When a roll-angle is transferred, through the main shaft assembly, to earn 106 the cam rotates and closes micro switch 1197 thereby enabling energization of the output relay 130.

Both micro switches, 105 and 167, are connected to one side of the D.C. power supply 26. Serially connected between the micro switch 105 and the other side of the D.C. power supply is a solenoid 12% in parallel with the serially connected resistor 121 and diode 122. Thus, when the starboard roll is satisfactory micro switch 165 closes completing a D.C. circuit thereby energizing the solenoid which is connected to a ganged relay for closing switches 123 and 124. The closure of switch 124 completes a D.C. path across power supply 26 causing illumination of safe starboard roll indicator 125. C10- sure of micro switch 119?, indicating the existence of a safe launch angle, completes another D.C. path thereby illuminating the safe-to-fire indicator 126. Further, with the coincidence of the closures of micro switch 107 and switch 123, which is caused by the closure of micro switch 1195, another D.C. path is completed. This D.C. path includes switch 123 and the serially connected parallel circuit of solenoid 131 and resistor 132 and diode 133 which resistor and diode are serially connected. Through the energization of solenoid 131 relay is actuated causing completion of the firing circuit through leads 141 selected when both SLAG systems operate. when the right system or both systems are in operation of switch 146. Of course, closure of relay 134 also completes through leads 142 of switch 149 a circuit from the torque transmitters 109 and 100' to remote indicators 112 and 112'. Through leads 142 of switch 14% both remote indicators 112 and 112 will operate to indicate the launch conditions of the ship. The system selector switch 140 selects either the left, right, or both SLAG systems by selecting the left output relay 130, right output relay 130', or both output relays. Since both torque transmitters and 10th of the SLAG systems cannot be employed to drive the remote indicators 112 and 112 only one is connected to the output when switch 146 selects both systems. As can be clearly seen in FIGS. 3A, 3B, 3C, and 3]), contacts 143 of switch 140, which will be connected to the remote indicators through output leads 142 when both systems are selected, are connected only to the torque transmitter 100'.

An analog computer as best seen in FIGS. 6A and 6B may be employed with the SLAG system of FIGS. 3A 3D. The analog computer input is the voltage output of linear transformer 150 which is mounted on the main shaft assembly of the mechanism assembly 80. This output is, therefore, a voltage proportional to the roll angle 0 of the ship. Each half of the dual SLAG system employs a separate computer connected to lead 151 and 151'. Where for purposes of economy it is desirable to employ but one computer the output of linear transformers b and 150', as best seen in FIG. 5, are connected to one of the ganged switches of selector switch 140. In this manner contact 145 is selected when the right SLAG system operates, or contact 146 is selected when the left SLAG system operates, or contact 144 is That is,

linear transformer 150 will provide the input to the computer but when only the left system is in operation linear transformer 150 will provide the computer input.

The SLAG analog computer, the principal components of which being shown shown schematically by block diagram in FIGS. 6A and 6B, is employed to solve Equation 30:

A sin ZB -l-BG cos 6 -C O where 0 is the input angle and varies between plus and minus 30.

A is a constant of the order of 6G (numerical), B is a constant of the order of 6 (numerical), and C is a constant of the order of 30 (numerical).

The computer is highly reliable since it employs A.C. induction rotating components and static transistor-mag- I netic amplifiers. Since the input data and solution varies at a relatively slow rate, electromechanical A.C. computing may be utilized eliminating the need for less reliable electronic solutions.

Servo positioner module 2%" receives its input as a voltage E0 proportioned to the ships roll angle 0 from a remote, shaft-driven linear transformer 150 mounted on the main shaft assembly the mechanism assembly iii) of FIGS. 3A-3D. This voltage is converted in module to a shaft angle by being applied through an amplifier 20 2 to a servo motor 293 after being conditioned at 201 by the feedback voltage from linear transformer 2%. The tachometer-generator 2M driven by motor 203 delivers an output voltage E0 of module Zt'itlE proportional to rate-of-change, or 9 (roll-rate).

T he output of generator 264 of module 264} is fed to a servo motor 223 of module 224} through an amplifier 222 after being conditioned at 221 by the feedback from generator 224 which is driven by servo motor 223. The input voltage is converted by the servo positioner in module 220 to integrated velocity or shaft angle 0 which is the original angle 0 minus the steady state component 0 Linear transformer 226 on the output shaft is driven through gear box 225 by servo motor 223 and thereby converts this angle to a proportional output voltage EG The output of module 209 is also converted to a shaft angle by servo motor 213 or module 210 after being conditioned at 211 by the feedback voltage from linear transformer 216 and, with the feedback voltage from generator 2'14, fed through the amplifier 212. The servo motor 218 is stopped at maximum shaft displacement by a gate 217 controlled by relay 2 18 at negative-going null of E6 the output from linear transformer 226 of module 228.

The maximum shaft displacement is converted to a proportional output voltage Efl roll-rate, by the linear transformer 216 which is driven on the output shaft by servo motor 213 through gear box 215.

The output of module 220, E0 is converted in the position sen o of module 26st? by applying this voltage to servo motor 233 after being conditioned at 231 by the feedback voltage from linear transformer 236 and, with the feedback from generator 234, fed through amplifier 232. However, theservo motor 233 is stopped at maximum shaft displacement by a gate 23-7 controlled by relay 238 at the negative-going null of roll-rate voltage E9 which is the output from linear transformer 266 of module 2599. The maximum shaft displacement is converted to a proportional output voltage 139,, roll-amplitude, by the linear transformer 236 which is driven on the output shaft by servo motor 233' through gear box 235.

Voltage EQ from the linear transformer 226 of module 229 is also fed through amplifier 24 2 to the servo motor 243 driving through gear box 245 of module 24% after being nulled against the output fed back from a driven resolver 246. Thus, a shaft angle is obtained which is ecgual to E3(; wts- EOI E0 is then converted to an output voltage vector Ewt by a driven synchro transmitter 247. Derived from the generator 245 which is driven by motor 243 in an output voltage EW which is proportional to roll frequency W.

The output voltage EW from generator 24-4 of module 240 is attenuated by potentiometer 258 connected to ground potential to obtain a voltage proportional to the product Wtd. This voltage Ewdt is fed to servo motor 253 of module 25%) after being conditioned at 251 by the feedback from linear transformer 256 and, with the feedback from generator 254, fed through amplifier 2 52 to thereby o tain a shaft angle Wtd. This shaft angle positions through a gear box 255 a synchro differential transmitter 257 in series with the wts syn-chro transmitter 247 of module 240 to obtain an output voltage vector tain a shaft angle proportional to W (ts-l-td). The shaft 7 positions two resolvers 265 and 265 which are excited respectively by output voltages Efi of module 230' and E of module 21%. The outputs of the resolvers 265 and 266 are then proportional respectively to:

The output from linear transformer 266 of module 220 is subtracted from sub-tractor ass from the output of linear transformer 206 of module 2th) to obtain a voltage E0 proportional to steady-state dis-placement. This voltage is then added by adder 269 to the output of roll resolver 265 of module 264 to obtain voltage proportional to 0 cos w(ts+td) +0 :0 the predicted launch angle. Position servo of module 27% applies the input voltage B0,, to servo motor 273 for driving through gear box 275 after it is conditioned at 271 by a feedback from linear transformer 27d and, with the feedback from generator 274, fed through amplifier 2-72. Thereby input voltage E6 is then converted to a shaft angle and the output of the linear transformer 276 on the shaft is a voltage E0 proportional to 6;, which may be read on a panel meter 2'79 and connected to other remote indicators through lead 192. The input EBH to resolver 277 is obtained from the output of an adjustable-gain amplifier 281. Amplifier 281 is fed a voltage 139;, from resolver 266 of module 269 after being conditioned at 2.80 by a tap from potentiometer 282 which is connected between the output of amplifier 281 and ground potential. The output of resolver 277 of module 27% is then EB cos 6 The input EA to resolver 278 of module 270 is obtained from a manually adjusted potentiometer 2-83 connected to ground potential. The output of resolver 278 is then A sin 20 Of course, to obtain these outputs from resolvers 2'77 and 278, resolver 277 must be capable of being positioned on the servo shaft at one speed and resolver 278 at two speeds. The outputs of resolvers 277 and 273 are then added to adder 284 to obtain From this sum is subtracted the output voltage from manually adjustable potentiometer 2555 which is connected to ground potential. This output voltage from potentiometer 285 is proportional to the quantity (1 thereby obtaining Equation 30.

This final resultant is then applied to a phase sensitive detector 288 through amplifier 287 to detect for Equation 30. Detection of Equation 30 causes actuation of relay 289 and thereby illuminating the GO light 190 and extinguishing the NO-GO light 1%.

The output voltage Ew from generator 244 of module 2461 which is proportional to roll frequency w, is converted to shaft velocity by the velocity servo of module 360. The servo motor 303 drives through the gear box 365 in response to the input voltage which is conditioned by feed back of generator 394 and fed through an amplifier 392 An electro-magnetic clutch 306 on the shaft of this servo motor engages, in response to the GO condition output from relay 289, a linear transformer 3% during the GO period, to integrate wT where T is GO duration. Since T T =T l/ w=wT G where T is period and w is roll frequency, percent of GO time is proportional to the output voltage from linear transformer 3&7 of module 3%. This voltage may be read by a panel meter 3&3 as percentage GO time and may also be connected to a plurality of other remote indicators through lead 3G9. Of course, a spring will be employed to return the linear transformer 3&7 to Zero at the end of each GO period.

A self-check switch 3ft} is provided at the input of the analog computer so as to provide the capability of checking the operation of the analog computer with a reference voltage to insure proper operation of the computer before actual operation is attempted.

Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims the invention may be practiced otherwise than is specifically described.

What is claimed and desired to be secured by Letters Patent of United States is:

1. A safe launch angle gate system for preventing missile launching from a marine vessel when missile fallback would damage said vessel and for allowing firing when safe fallback conditions exist comprising; a vertical gyro for sensing angular movement of said vessel about its longitudinal axis and having an output voltage proportional to the sine of said movement about said axis, switch means, actuating means electrically connected to said switch means and responsive to said vertical gyro output for indicating said vessels motion and for actuating said switch means when said vessel has achieved an angular relationship about its longitudinal axis with respect to the vertical to avoid missile fallback damage, said actuating means comprising; a main shaft assembly for operating said switch means, amplifier means, servo motor means for driving said main shaft assembly, and a control transformer connected through said amplifier means to said servo motor means; and relay means connected to said switch means for completing a missile firing circuit.

2. A safe launch angle gate as claimed in claim 1 wherein said switch means comprises a first cam member on said main shaft assembly and a first switch connected thereto for actuating a first relay of said relay means, and a second cam member on said main shaft assembly and a second switch for actuating a second relay of said relay means.

3. A safe launch angle gate system as claimed in claim 2 wherein said first cam member is connected to said main shaft assembly through a slip clutch for allowing, after said first switch closes, at least one degree angular movement in a safe direction and one degree back in an unsafe direction before said first switch reopens.

4. A safe launch angle gate system as claimed in claim 3 wherein said first relay comprises a resistor and a diode interconnected in series and a solenoid connected in par allel with said resistor and diode for closing a third and a fourth switch.

5. A safe launch angle gate system as claimed in claim 4 wherein said third switch is connected in series with said second relay and wherein said second relay comprises a resistor and a diode interconnected in series and a solenoid connected in parallel with said resistor and diode for closing a firing circuit.

6. A safe launch angle gate system as claimed in claim 5 wherein said main shaft assembly comprises a gearing means for controlling the rotor shaft of said control transformer whereby the output of said control transformer is proportional to the sine of the difference between the electrical input angle and the shaft angle of said control transformer.

7. A safe launch angle gate system as claimed in claim 6 wherein said amplifier means comprises a servo transistor amplifier and a stabilizing resistor connected between the output of said control transformer and the input to said amplifier for adjusting amplifier gain.

8. A safe launch angle gate system as claimed in claim 7 wherein said servo motor means comprises a high torque-to-inertia servo motor and a first tuning capacitor connected across the control phase of said servo motor for achieving a unity power factor at maximum efiiciency.

9. A safe launch angle gate system as claimed in claim 5 wherein said means responsive to said vertical gyro out put for indicating said vessels motion comprises a torque transmitter having a rotor connected to the reference phase of said servo motor, a torque repeater having a stator connected to the stator of said torque transmitter for indicating said angular motions of said vessel by rotation of the torque repeater rotor with respect to said torque repeater stator, and a second capacitor connected across the reference phase of said servo motor for tuning and for reducing residual voltage.

10. A dual safe launch angle gate system for preventing missile launching from a marine vessel when missile fallback would damage said vessel and for allowing firing when safe fallback conditions exist comprising; a first safe launch angle gate system having a first vertical gyro for sensing angular movement of said vessel about the longitudinal axis thereof and having an output voltage proportional to the sine of said movement about said axis, first switch means, first actuating means responsive to said first vertical gyro output for indicating said vessels angular motion and for actuating said first switch means when said vessel has achieved an angular relationship about its longitudinal axis with respect to the vertical to thereby avoid missile fallback damage, said first actuating means 13 comprising; a first main shaft assembly for operating said first switch means, first amplifier means, first servo motor means for driving said first main shaft assembly, and a first control transformer connected through said first amplifier means to said first servo motor; and first relay means connected to said first switch means; a second safe launch angle gate system having a second vertical gyro for sensing angular movement of said vessel about said longitudinal axis and having output voltage proportional to the sine of said movement about said axis, second actuating means responsive to said second vertical gyro output for indicating said vessels motion and for actuating said second switch means when said vessel has achieved an angular relationship about its longitudinal axis with respect to the vertical to thereby avoid missile fallback damage, said second actuating means comprising a second main shaft assembly for operating said second switch means, a second amplifier means, a second servo motor means for driving said second main shaft assembly, and a second control transformer connected through said second amplifier means to said second servo motor; second relay means connected to said second switch means; and a system selector switch having first contacts for selecting said first safe launch angle gate system and having second contacts for selecting said second safe launch angle gate system for closing a firing circuit while both said first and second safe launch angle gate systems are available to determine the presence of a safe launch angle should the other system fail.

11. A dual safe launch angle gate system as claimed in claim wherein said system selector switch has a third set of contacts whereby both said first and second safe launch angle gate systems can operate simultaneously to close said firing circuit.

12. A dual safe launch angle gate system as claimed in claim 10 wherein said first switch means comprises a first cam member on said first main shaft assembly and a first switch connected thereto for actuating a first relay of said first relay means, and a second cam member on said first main shaft assembly and a second switch connected thereto for actuating a second relay of said first relay means; and wherein said second switch means comprises a third cam member on said second main shaft assembly and a third switch connected thereto for actuating a third relay of said second relay means, and a fourth cam member on said second main shaft assembly and a fourth switch connected thereto for actuating a fourth relay of said second relay means.

13. A dual safe launch angle gate system as claimed in claim 12 wherein said first and third cam members are connected respectively to their first and second main shaft assemblies through respective first and second slip clutches for allowing, after said first and third switches close, at least one degree angular movement in a safe direction and one degree back in an unsafe direction before said respective first and third switches reopen.

14. A dual safe launch angle gate system as claimed in claim 13 wherein said first relay of said first relay means comprises a resistor and a diode interconnected in series and a solenoid connected in parallel with said resistor and diode for closing a fifth switch and a sixth switch and wherein said third relay of said second relay means comprises a resistor and a diode interconnected in series and a solenoid connected in parallel with said resistor and diode for closing a seventh and an eighth switch.

15. A dual safe launch angle gate system as claimed in claim 14 wherein said fifth switch is connected in series with said second relay of said first relay means and wherein said second relay of said first relay means comprises a resistor and a diode interconnected in series and a solenoid connected in parallel with said resistor and diode; and further wherein said seventh switch is connected in series. with said fourth relay of said second relay means and wherein said fourth relay comprises a resistor and a diode interconnected in series and a solenoid connected in parallel with said resistor and diode whereby said second relay of said first relay means connects said first safe launch angle gate system to said system selector switch and said fourth relay connects said second safe launch angle gate system to said system selector switch for closing a firing circuit.

16. A dual safe launch angle gate system as claimed in claim 15 wherein said first main shaft assembly comprises a first gearing means for controlling the rotor shaft of said first control transformer and wherein said second main shaft assembly comprises a second gearing means for controlling the rotor shaft of said second control transformer whereby the outputs of said first and second control transformers are proportional to the sine of the diiference between the electrical input angles thereto and the shaft angles of said first and second control transformers.

l7.- A dual safe launch angle gate system as claimed in claim 16 wherein said first amplifier means comprises a first servo transistor amplifier and a first stabilizing resistor connected between the output of said first control transformer and the input to said first amplifier for adjusting the amplifier gain, and wherein said second amplifier means comprises a second servo transistor amplifier and a second stabilizing resistor connected between the output of said second control transformer and the input to said second amplifier for adjusting amplifier gain.

18. A dual safe launch angle gate system as claimed in claim 17 wherein said first servo motor means comprises a first high torque-to-inertia servo motor and a first tuning capacitor connected across the control phase of said first servo motor for achieving a unity power factor at maximum eificiency, and wherein said second servo motor means comprises a second high torque-to-inertia servo motor and a second tuning capacitor across the control phase of said second servo motor for achieving a unity power factor at maximum efficiency.

19. A dual safe launch angle gate system as claimed in claim 15 wherein said first means responsive to said first verticm gyro output for indicating said vessels motion comprises a first torque transmitter having the rotor thereof connected to the reference phase of said first servo motor and having its stator electrically connected to said first system selector switch contacts, a first and a second torque repeater having the stators thereof connected to said system selector switch for indicating said angular motions of said vessel by rotation of said first and second torque repeater rotors with respect to the stators thereof; further wherein said second means responsive to said second vertical gyro output for indicating said vessels motion comprises a second torque transmitter having the rotor thereof connected to the reference phase of said second servo motor having its stator electrically connected to said second system selector switch contact; and further wherein said third set of contacts of said system selector switch are electrically connected to said first system selector switch contacts whereby said first torque transmitter is electrically connected through said system selector switch to said first and second torque repeaters when said first safe launch angle gate system is in operation and when both said first and second safe launch angle gates systems are in operation and whereby said second torque transmitter is electrically connected to said first and second torque repeaters when said second safe launch angle gate system is in operation.

26. An analog computer for computing future longitudinal angles for marine vessels comprising; an input proportional to said vessels roll angle, first computing means responsive to said input for converting said input to a voltage signal proportional to said vessels roll-rate, second computing means electrically connected to said first computing means for converging said roll-rate signal to a voltage signal proportional to said vessels integrated roll velocity, third computing means electrically connected to said first computing means for converting said roll-rate signal to a voltage signal proportional to said ships maxil mum roll-rate, fourth computing means electrically connected to said second computing means for converting said integrated roll velocity signal to a voltage signal proportional to said ships roll amplitude, fifth computing means electrically connected to said second computing means for converting said integrated roll velocity signal to a first voltage signal proportional to the vessels roll frequency at the time of missile firing and a second voltage signal proportional to the missile roll frequency, means electrically connected to said fifth computing means for attenuating said second output voltage signal of said fifth computing means to induce a delay time, sixth computing means electrically connected to said attenuating means and being responsive to said attenuated signal and to said first output voltage signal of said fifth computing means for converting said signals to an output voltage signal proportional to roll frequency at a time in excess of missile firing time, means for subtracting said first computing means output voltage signal proportional to roll-rate and said second computing means output voltage signal proportional to integrated roll velocity for thereby obtaining a voltage signal proportional to steady-state displacement, seventh computing means electrically connected to and responsive to said sixth computing means output voltage signal, said seventh computing means having a first resolver means electrically connected to and responsive to said roll amplitude voltage signal for thereby deriving an output, which, when added to said voltage signal proportional to steady-state displacement, is proportional to a future launch angle, said seventh computing means also having a second resolver means electrically connected to and responsive to said maximum roll-rate voltage signal for thereby deriving an output voltage signal proportional to said vessels roll-rate at said future launch angle, an adder, eighth computing means electrically connected and responsive to said voltage signal proportional to said future launch angle and having an output proportional to said predicted launch angle, and said eighth computing means further having third and fourth resolvers having the outputs thereof connected to said adder, first potentiometer means for introducing a first constant voltage to said third resolver, secondpotentiometer means connected to said second resolver output for introducing therewith a constant voltage to said fourth resolver and a third potentiometer means connected to the output of said adder for subtracting a constant voltage from said computer and thereby predicting the angle of said marine vessel with respect to said vertical plane through said longitudinal axis at a future time approximately equivalent to the time required to initiate missile firing and for said missile to clear the launcher muzzle.

21. An analog computer for computing future launching angles from a marine vessel such as that claimed in claim including; first indicator means connected to said computing means for indicating said vessels roll angle, second indicator means connected to said computing means for indicating the percentage of firing time remaining in a safe firing period, means connected to said computing means for detecting a prescribed future angular relationship for safe firing conditions free of fallback hazards, third indicator means, and means connected to said detector means and said third indicator means for conditioning said second and third indicators in response to safe conditions detected by said detection means thereby indicating the presence of said safe conditions whereby launching may be initiated causing missile exit from a launcher muzzle when said vessel is at a safe launching angle with respect to said vertical plane.

22. An analog computer as claimed in claim 21 wherein said first indicator means is electrically connected to said eighth computing means output which is proportional to said future launch angle whereby said vessels roll angle may be visually indicated.

23. An analog computer as claimed in claim 22 wherein said second indicator means comprises a ninth computing means electrically connected and responsive to said fifth computing means, second output signal proportional to said vessels roll frequency and having means responsive to said activating means during safe launch periods for deriving to indicators an output signal proportional to the percentage of safe launch time remaining in a safe launch period.

24. An analog computer as claimed in claim 23 wherein said conditioning means comprises a relay and wherein said third indicator means comprises safe and unsafe illuminators connected to said relay.

25. A safe launch angle gate system for preventing missile launching from a marine vessel when missile fallback would damage said vessel and for allowing firing when safe fallback conditions exist comprising; a vertical gyro for sensing angular movement of said vessel about its longitudinal axis and having an output voltage proportional to the sine of said movement about said axis, switch means, actuating means responsive to said vertical gyro output for indicating said vessels motions and for actuating said switching means when said vessel has achieved an angular relationship about said longitudinal axis with respect to said vertical plane to avoid missile fallback damage, said actuating means comprising; a main shaft assembly for operating said switching means, a linear transformer mounted on said main shaft assembly having an output proportional to said vessels roll angle for providing an input to said computer, an amplifier means, a servo motor means for driving said main shaft assembly, and a control transformer connected through said amplifier means to said servo motor means; relay means connected to said switch means for completing a fire circuit, and an analog computer for predicting future launch angles and indicating the future existence of safe launch angles.

26. A safe launch angle gate system as claimed in claim 25 wherein said computer comprises an input means responsive to said input from said linear transformer proportional to said vessels roll angle for computing future angular relationships of said marine vessel during rotation about the longitudinal axis thereof with respect to a vertical plane parallel to said longitudinal axis, first indicator means connected to said computing means for indicating said ships roll angle, second indicator means connected to said computing means for indicating percentage of firing time remaining in a safe firing period, means connected to said computing means for detecting a prescribed future angular relationship having safe firing conditions free of fallback hazards, third indicator means, and means connected to said detector means and said second and third indicator means for conditioning said second and third indicators in response to detection of safe conditions by said detection means thereby indicating the presence of said safe conditions by said indicators whereby launching may be initiated causing missile exit from a launcher muzzle when said vessel is at a safe launching angle with respect to said vertical plane.

27. A safe launch angle gate system as claimed in claim 26 wherein said switch means comprises a first cam member on said main shaft assembly and a first switch connected thereto for activating a first relay of said relay means, and a second cam member on said main shaft assembly and a second switch for actuating a second relay of said relay means.

28. A safe launch angle gate system as claimed in claim 27 wherein said first cam member is connected to said main shaft assembly through a slip clutch for allowing, after said first switch closes, at least one degree angular movement in a safe direction and one degree back in an unsafe direction before said first switch reopens.

29. A dual safe launch angle gate system for preventing missile launching from a marine vessel when missile fallback would damage said missile and for allowing firing when safe fallback conditions exist comprising; a first safe launch angle system having a first vertical gyro for sensing angular movement of said vessel about the longitudinal axis thereof and having an output voltage proportional to the sine of said movement about said axis, first switching means, first actuating means responsive to said first vertical gyro output for indicating said vessels motions and for actuating said first switching means when said vessel has achieved an angular relationship about said longitudinal axis with respect to the vertical to thereby avoid missile fallback damage, and first relay means connected to said first switching means; a second safe launch angle gate system having a second vertical gyro for sensing angular movement of said vessel about said longitudinal axis and having an output voltage proportional to the sine of said movement about said axis, second switching means, second actuating means responsive to said vertical gyro output for indicating said vessels motions and for actuating said second switching means when said vessel has achieved an angular relationship about said longitudinal axis with respect to the vertical to thereby avoid missile fallback damage, and second relay means connected to said second switching means; said first and second actuating means comprising respectively first and second main shaft assemblies for operating said first and second switching means, a first and second linear transformer mounted to'first and second main shaft assemblies having an output proportional to said vessels roll angle for providing an input to said computing means, a first and second amplifier means, a first and second servo motor means for respectively driving said first and second main shaft assemblies, and a first and second control transformer connected through said respective first and second amplifier means to said first and second servo motor means; a system selector switch having first contact for selecting said first safe launch angle gate system and having second contact for selecting said second safe launching angle gate system for closing a firing circuit; and means connected to said dual safe launching angle gate system for computing future launch angles and for indicating future existence of safe launching angles.

30. A dual safe launch angle gate system as claimed in claim 29 wherein said computer means comprises an input from said first linear transformer, first means for computing a future angular relationships of said marine vessel during rotation about the longitudinal axis thereof with respect to a vertical plane parallel to said longitudinal axis, first indicator means connected to said first computing means for computing said vessels roll angle, second indicator means connected to said firstcomputing means for indicating the percentage of firing time remaining in a safe firing period, first means connected to said first computer means for detecting a prescribed future angular relationship having safe firing conditions free of fallback hazards, third indicator means, and first activating means connected to said first detector means and said second and third indicator means for activating said second and indicator means in response to detection of safe conditions by said detecting means thereby indicating the presence of safe launch conditions; and wherein said computer means further comprises an input from said second linear transformer, second means for computing future angular relationships of said marine vessel rotating about said longitudinal axis with respect to said vertical plane parallel to said longitudinal axis, fourth indicator means connected to said computing means for indicating said vessels roll angle, fifth indicator means connected to said computing means for indicating percentage of firing time remaining in a safe firing period, second means connected to said second computing means for detecting a prescribed future angular relationship having safe firing conditions free of fallback hazards, sixth indicator means, and activating means connected to said second detector means and said fifth and sixth indicator means for activating said fifth and sixth indicator means in response to detection of safe conditions by said second detecting means thereby indicating the presence of safe conditions on said indicators whereby launching may be initiated causing missile exit from a launcher muzzle when said vessel is at a safe launching angle with respect to said vertical plane.

31. A dual safe launch angle gate system as claimed in claim 29 wherein said outputs of said first and second linear transformers are electrically connected to said system selector switch for electrically connecting the output of said first linear transformer to said computer means when said first safe launch angle gate system is in operation and when both said first and second safe launch angle gate systems are in operation, and for electrically connecting the output of said second linear transformer to said computer means when only said second safe launch angle gate system is in operation.

32. A dual safe launch angle gate system as claimed in claim 31 wherein said computer means comprises an input proportional to said vessels roll, means for computing future relationships of said marine vessel during rotation about said longitudinal axis with respect to said vertical plane, first indicator means connected to said computing means for indicating said vessels roll-angle, second indicator means connected to said computing means for indicating percentage of safe firing time remaining in a safe firing period, means connected to said computing means for detecting a prescribed future angular relationship having safe firing conditions free of fallback hazards, third indicator means, and actuating means connected to said detector means and said second and third indicator means for activating said second and third indicator means in response to detection of safe conditions by said detection means thereby indicating the presence of said safe conditions whereby launching may be initiated to cause a missile exit from a launcher muzzle when said vessel is at a safe launching angle with respect to said vertical plane.

References Cited in the file of this patent UNITED STATES PATENTS 1,452,484 Sperry Apr. 17, 1923 2,394,021 Stone Feb. 5, 1946 2,463,687 Gittens Mar. 9, 1949 

1. A SAFE LAUNCH ANGLE GATE SYSTEM FOR PREVENTING MISSILE LAUNCHING FORM A MARINE VESSEL WHEN MISSILE FALLBACK WOULD DAMAGE SAID VESSEL AND FOR ALLOWING FIRING WHEN SAFE FALLBACK CONDITIONS EXIST COMPRISING; A VERTICAL GYRO FOR SENSING ANGULAR MOVEMENT OF SAID VESSEL ABOUT ITS LONGITUDINAL AXIS AND HAVING AN OUTPUT VOLTAGE PROPORTIONAL TO THE SINE OF SAID MOVEMENT ABOUT SAID AXIS, SWITCH MEANS, ACTUATING MEANS ELECTRICALLY CONNECTED TO SAID SWITCH MEANS AND RESPONSIVE TO SAID VERTICAL GYRO OUTPUT FOR INDICATING SAID VESSEL''S MOTION AND FOR ACTUATING SAID SWITCH MEANS WHEN SAID VESSEL HAS ACHIEVED AN ANGULAR RELATIONSHIP ABOUT ITS LONGITUDINAL AXIS WITH RESPECT TO THE VERTICAL TO AVOID MISSILE FALLBACK DAMAGE, SAID ACTUATING MEANS COMPRISING; A MAIN SHAFT ASSEMBLY FOR OPERATING SAID SWITCH MEANS, AMPLIFIER MEANS, SERVO MOTOR MEANS FOR DRIVING SAID MAIN SHAFT ASSEMBLY, AND A CONTROL TRANSFORMER CONNECTED THROUGH SAID AMPLIFIER MEANS TO SAID SERVO MOTOR MEANS; AND RELAY MEANS CONNECTED TO SAID SWITCH MEANS FOR COMPLETING A MISSILE FIRING CIRCUIT. 